ECP 6 Flashcards
What are the 7 halsted principles during surgery
- Observe strict aseptic technique
- Thorough knowledge of anatomy and technique
- Control haemorrhage meticulously
- Gentle tissue handling
a. Every damaged cell placed additional demands on the body’s recovery mechanisms
b. Appropriate location of incisions and adequate incision length - Preserve blood supply to tissues
a. Anatomy is important - Accurate tissue apposition with minimal tension
- Eliminate dead space
○ Dead space predispose to seroma formation and infection
What is important to reduce infections rates during surgery, how does anaesthesia mask bleeding and what does blood do to the operative field
- Surgical lavage reduces infection rates : ‘the solution to pollution is dilution’.
- Bear in mind that anaesthetic agents cause hypotension and hypothermia which both reduce/mask the amount of bleeding
- Blood within the operative field
○ Obscures visualisation
○ Irritates tissue
○ Prevents tissue apposition
○ Delays healing
○ Potentiates infection
Haemostasis via pressure/tamponade and ligation what need to do
- pressure/tamponade -> take 30seconds for a soft clot to form then 2-3 mins for cross-linking of fibrin, guaze swab used to compress and blot
- Ligation - best for secruity, 3 forceps method -> most proximal haemotstat removed and ligature positioned in crushed tissue, then transected between two more distal haemostatic forceps, OR trasnfixing liguature -> placed distal to simple ligature
List 9 reasons you may need to do a exploratory laparotomy
- GI disorders –Foreign bodies / torsion / rupture
- Urogenital abnormalities unresponsive to medical Rx
- Abdominal disorders of unknown origin
- Penetrating trauma
- Acute abdomen
- Generalized peritonitis
- Diagnosis and treatment of portosystemic shunts
- Splenic abnormalities
- Uncontrolled abdominal haemorrhage
When should you do a laparotomy and the 4 main approaches, when to use what
- Patient stabilized OR patient not stabilizing with appropriate supportive therapy
1) ventral midline - most common
2) paracostal - increased exposure of liver
3) flank - ovariohysterectomy/gastropexy
4) retroperitoneal - adrenal neoplasia
What are the 5 main steps in exploratory laparotomy after open abdominal cavity
- Remove Falciform ligament - Aids visualisation
- Suction any peritoneal fluid
- Place Balfour retractors
a. Moistened lap. Sponges
b. Care not to incorporate viscera - Elevate xiphoid to visualize diaphragm, liver and cardia
- Systematic exploration
○ Cranial to caudal, body system -> left to right
○ Colour, texture, shape or viscera / organs
○ Assess movement of gastrointestinal tract
○ Palpate pulses in vessels
Cranial and cranial left quadrant of abdomen what present within
- Diaphragm
- Liver and gall bladder
○ Colour, margin sharpness, focal lesions, texture
○ Gall bladder expressible - Stomach
○ Gastroesophageal sphincter through oesophageal hiatus.
Cranial right quadrant of abdomen what present within
- Duodenum
○ Use meso-duodenum to retract viscera to midline to expose right side of abdomen
○ Anchored by duodenocolic ligament caudally - Pancreas
- Portal vein and caudal vena cava
- Right kidney and adrenal
Caudal left quadrant of abdomen what present within
- Spleen
- Rectum, Colon, Caecum
- Mesenteric root and LN
- Ileum –anti mesenteric vessel
- Jejunum
- Back to duodenum at duodenal colic ligament
- Mesocolon to retract viscera to expose left abdomen to visualize left kidney and adrenal
○ Can see aorta from this position
caudal right quadrant of abdomen what present within
- Bladder and ureters
- Prostate or uterus / ovaries
- Open omental bursa to visualize L limb pancreas
What samples can you take from exploitative laparotomy
Clin path -> culture, sensitivity, cytology, biochemsitry
- swabs or fluid sample
- biopsy -> skin punch biopsy with #11 scapel in GIT, liver, spleen, pancrease
What are the 4steps in laparotomy closure
1) lavage abdomen with warmed 0.9%NaCl - 20-50ml, should be clear
2) external rectus sheath need to incorape into peritoneum
3) close from caudal to cranial direction with continuous appositional suture pattern - synthetic, slow absorbable monofilament
4) SC layers -> 2 layers to decrease dead space -> fast absorption for beneath - subcut
non-absorbale simple interrupted pattern for skin
What are 9 important complications of laparotomy
1. Hypothermia ○ Need active rewarming ○ ideally minimization of heat loss during anaesthesia and surgery ○ Especially in small dogs/cats, young animals 2. Seroma - pocket of serous fluid that can develop within the body after surgery 3. Dehiscence and evisceration 4. Foreign materials left in abdomen ○ Instruments ○ Gauze sponges “gossypiboma” 5. Adhesions ○ Restrictive or non-restrictive 6. Peritonitis 7 Infection 8. Self-trauma –suture knots too tight 9. Skin irritation –clipper reaction
Laparoscopy (keyhole surgery) what occurs and indications for its use
- Minimally invasive alternative to open laparotomy procedure Telescope camera placed intra-abdominally through a trocar. Indications: - Abdominal cryptorchid testes - Ovariectomy / ovariohysterectomy - Liver biopsy - Lap-assisted gastropexy - Lap-assisted cystotomy
What are some clinical consequences of cancer
- Expansile growth
- Destruction of host tissues and function
- Infiltration and metastasis
- Necrosis, ulceration and haemorrhage
- Cachexia - massive body mass loss
- Hormone production - hyperCa
- Reduced quality of life
- Reduced lifespan
What are the 3 main steps in diagnosis of a tumor and what is needed for almost all treatment planning
1. What is it? ○ Neoplastic or non-neoplastic ○ Tumour type/cell of origin? § Round cell, epithelial or mesenchymal 2. How bad is it? ○ Benign or malignant? Grade? 3. Where is it? ○ Clinical staging (spread/extent of cancer) § TNM system A cytologic or histopathologic diagnosis is required in almost all cases
What are the 2 common diagnostic techniques for cancer diagnosis
1. Fine needle aspiration (FNA) for cytology (22g needle) ○ Aspirational vs non-aspirational techniques 2. Surgical biopsy for histopathology ○ Incisional biopsy § Needle core biopsy § Skin punch biopsy § Surgical wedge biopsy § Bone biopsy ○ Excisional biopsy § Removal with margin of normal tissue
What is the difference between aspirational and non-aspirational FNA and which do first
Aspirational - try second
- pull back plunger 1/2 way using negative pressure to aspirate cells and redirect needle 3-5 times then release plunger while still in mass
Non-aspirational - try first
- uses needle only - popping needle in and out, uses capillary action, no suction
describe sample preparation for cytology slides
- Label the glass slide ○ Animal name (first and last) ○ Site § Tissue, organ, location ○ Date - Leave slide to air-dry - Stain with quick stain (if analysis in-house) ○ Tips - use pencil and keep slides away from formalin (alters cell morphology)
What are 7 indications for biopsy
- If FNA cytology non-diagnostic or equivocal
- If type of treatment would be altered
- If extent of treatment would be altered
- Owners willingness to treat would change
- Malignant neoplasia - to grade and plan
- Major or reconstructive surgery is required
- Goal is diagnosis for prognostic purposes
What are important in terms of biopsy tract and scars and what is important with tissue handling
- Biopsy tract must be placed so that it can be removed with definitive surgery
- Biopsy scars or needle tracts are considered contaminated and potentially seeded by neoplastic cells
Handling - Use shape surgery technique
- Avoid electrocautery
- Avoid ulcerated/inflamed tissue
- Handle tissue delicately
- One specimen per container
- thickness: maximum 2cm for formalin
Incisional biopsy when use, what to take and the 4 types with what type of lesions
When complete removal not possible
- Multiple biopsies
- For cores, at least 5mm long
Types
1. Needle biopsy (Bind vs U/S guided) - multiple samples through same skin incision = more tissue = diagnosis
2. skin punch biopsy - percutaneous for superficial lesions
3. surgical wedge - larger piece of tissue can be obtained
4. bone biopsy - advance through the cortex
Excisional biopsy when to use and what does it gain information on
○ Do if surgical dose NOT altered by knowledge of tumour type § Eg - splenectomy for splenic mass ○ Benign tumor based cytology § Lipoma ○ Lymph node § Staging ○ Provides grade information ○ Goal: diagnosis and treatment § Anatomic location allows wide margins
Biopsy submission what are the 4 steps
- Incomplete parallel cuts (1cm apart) can be utilised to assist with appropriate tissue fixation and orientation for large specimens
Want to keep deep margin intact while doing this - label container
- identify marginal - ink, suture ( Single sutures = lateral margins, Two sutures = caudal margins) - NEED TO INFORM PATHOLOGIST ABOUT WHAT YOU CHOOSE
- complete submission form - signalment, history, description, potential diagnosis thoughts
Grading of neoplasm what is the histopathogical criteria and for type of tumor and what does grading information provide
- Pathologists grade tumor’s using histopathological criteria
○ Degree of cellular differentiations (pleomorphism)
○ Number of mitotic figures (growth rate)
○ Degree of necrosis/haemorrhage
○ Evidence of local invasion
○ Presence of metastasis (vascular and lymphatic) - Grading criteria varies with the type of tumour
○ Reports as low vs high grade or numerical grade 1-3 - Grading provides information on the potential behaviour of the tumor
Pathology reports what should you do with it
- Read and interpret the report yourself
○ Always get detailed report, not summary
○ Check that it fits with the clinical picture - What if report does not fit clinical picture
○ Speak with the pathologist (they don’t bite)
○ May perform re-cuts of the biopsy specimen or obtain a second opinion on the FNA or biopsy
What is clinical staging for a neoplasm, what system should is generally used
Knowledge of tumour type, grade and stage dictates surgical dose TNM System developed by WHO T = tumour characteristics § T15 = 15cm diameter tumour N = regional lymph node involvement § N0 = no node enlargement § N1 = regional node enlargement § N2 = next node in chain is enlarged M - metastatic involvement § M0 - no metastases § M1 - metastases present
What are the 8 steps in the clinical staging of neoplasms
- Detailed history
- Thorough clinical and physical examination
- Examination of mass (T)
○ Size, location, firmness and adherence to underlying structures - Staging tests are based on results of biopsy
- Examination of draining lymph nodes (N)
○ Palpation/FNA cytology/biopsy - Imaging +/- cytology/biopsy of distant organs (M)
○ Lungs, abdominal organs, LN, liver - Clinical pathology testing:
○ Haematology, biochem, urinalysis
§ Intercurrent diseases (may modify prognosis)
§ Other organ involvement (liver/kidney) - Diagnostic imaging (M)
○ Based on knowledge of metastatic pattern for a given tumour type
§ Abdominal ultrasound (liver, LNs)
§ Thoracic radiographs (3 views)/CT for lung metastases
Cattle temperature, heart rate and respiratory rate
38.5 - 39.2 degrees Celsius
Normal = 60-80 bpm. >150 = poor prognosis.
Rate: 20-30 in mature dairy; 12-30 in mature beef
Preoperative evaluation of surgical oncology patient what are the 6 steps
- What is it? –FNA cytology, biopsy
- How bad is it? –Benign/malignant, Grading
- Where is it? -Clinical staging, TNM
- Patient status
- Treatment options
- Treatment planning
Patient status
1) thorough physical examination
2) peri-or pre-operative management - antihistamines, management of cardiovascular effects
3) laboratory work (CBC, biochem, U/A)
4) cardiopulmonary status
what is the most important consideration in treatment options and what factors are involved
- Maintain quality of life
○ Treatment should not be worse than disease
○ We should do things for the patient, not to the patient
Patient factors: - Anatomic location / concurrent Dz / morbidity
Owner factors:
○ cost / time / emotion / previous experience
Surgical planning what is it apart of, what does it require knowledge of and what does this lead to
- Surgery may either be the sole form of treatment or part of a multidisciplinary protocol:
Surgery, radiation, chemotherapy - Knowledge of tumour type, grade and stage dictates surgical ‘dose’ (margins)
- Assessment of depth and invasion of tumour may require advanced imaging for surgical margin planning
surgical oncology principles 3 main ones and how to submit lump
1) do not compromise aggressiveness of surgery to allow easy wound closure
2) gentle tissue handling
3) lavage exision bed - preventing seeding of tumor
- Submit the ENTIRE SPECIMEN not pieces, label with history, signalment, pathology findings, identify margins
What are the 3 pieces of information that the histopathology report provides and what is involved with post-operative assessment
1) Diagnosis–cell of origin
2) Grade (invasion, MI)
3) Assessment of adequacy of margins
Post-op
- response to treatment
- complications
- continued treatment planning
- matching outcome to goals of clinician and owner
- patient quality of life
In terms of oncology what are the 6 main roles of surgery
1) prevention - ovariohysterectomy
2) diagnosis - biopsy
3) cure - first surgery best chance, needs to be early in disease, aggressive, if in doubt refer
4) palliation - improve quality of life not length - need to communicate goal eg excision of ulcerated bleeding mass
5) cytoreduction - should enhance efficacy of other treatments
6) oncologic related treatment such as feeding tubes, pleural or peritoneal drainage tubes
Cryosurgery when to conduct, how work and examples of chemicals used
When conduct: ○ Small masses - Eyelid / ear / nose tumours ○ SCC / histocytoma ○ Animals not suited for anaesthesia / surgery Mechanism - Controlled use of freeze/thaw cycles to destroy tissues Mechanisms of cell death: (-22˚C) - disrupts cell membranes, osmotic gradient - dehydration and vascular collapse Cryogens a. Nitrous Oxide § Small tumours only b. Liquid Nitrogen: § Spray (less control) § Probe
Cryosurgery what happens to the tissue and 2 advantages and disadvantages
- Vascular stasis and cell death results in a slough which will heal via second intention (3-6 weeks)
- Depigmentation occurs - hair grows back white
- Advantages
○ Cheap, can use with sedation
○ Can repeat therapy if required - Disadvantages
○ No tissue diagnosis if no pre-treatment biopsy
Lack of ability to assess tissue margins
Radiation therapy main issue, how works, dosage and what tumors used for
Requires specialised equipment
How works
○ Ionising radiation causes cell death via application of energy to DNA -single or double strand breaks
- Proliferating cells are radiation sensitive
Dosage
a. Radiation delivered in small daily (Mon–Fri) fractions - (1.5 –3Gy) to total 42-57 Gy
- . Coarse fraction XRT – larger fractions 1-2x/week (less frequency than above)
For palliative treatment
Tumours where radiation is used
- Nasal carcinomas
- Brain tumours
- Thyroid carcinoma
- Oral tumours (SCC, MM)
- Incompletely excised MCT and STS
What are some roles of the GP in veterinary medicine
- Diagnosis (often)
- Additional diagnostic tests & interpretation
- Basic information about treatment options and prognosis
- Offer referral
- Treatment
- Some maybe done in general practice
§ Palliative care
§ Chemotherapy (?) - Client education and support
○ Information
○ Acknowledge fear, stress
Clear, honest, non-judgemental communication
What are survival times with cancer when occur and what is important with animals
- Median survival time = 50% of the population is alive at this time in that study
○ Usually post-diagnosis
○ Usually overall survival, not cancer specific survival
How is tumor growth and treatment related
More sensitive during rapid growth phase (increased % rapidly dividing cells)
- Rapid growth generally occurs before clinically detected -> generally why chemotherapy not recommended with large tumours -> surgery then chemotherapy
Local vs Systemic cancer treatment when use and examples
1) local
- primary tumor, local LN, surgery, radiation
2) Systemic
- Known or high risk systemic disease (high risk want to get at clinically undetectable stage)
○ E.g. Lymphoma – known systemic disease; osteosarcoma – high risk systemic disease, chemotherapy used as adjuvant Tx after surgery
- Usually NOT recommended as first choice for local control.
○ May be considered in some cancers if surgery, radiation are not options
- Chemotherapy
- Immunotherapy
What are 4 important chemotherapy general principles
1) fewer cells = more likely to be effective
2) multiple doses -> not all cells equally sensitive at all times, recommend 6 cycles
3) multiple drugs - difference mechanism of action less cross resistance
4) chemoresistance is likely to result in treatment failure - MDR1/ABCB1/P-glycoprotein results in multi-drug resistant phenotype -> hyperfunctional pump out drugs, IF NOT SICK DONT GIVE STEROIDS
Chemotherapy dosing how generally occurs and what increases chance of side effects
1) body surface area not weight
2) Maximum tolerated dose
○ Highest dose not associated with unacceptable side effects based on study populations
MDR1/ABCB1/P-glycoprotein mutation - COLLIES, SHELTIE, AUSTRALIAN SHEPHERD - test for mutation as has impaired drug clearance and therefore change in toxicity levels
What are the 3 main chemotherapy side effects
BAG
- bone marrow
- alopecia
- gastrointestinal
In terms of bone marrow effects from chemotherapy what occurs and the 3 main clinical signs
Immature haematopoietic cells affected - Shorter circulating lifespan = first affected
□ Neutrophils < platelets < RBC
1) Neutropenia
○ If neutropenia + febrile/ill -> hospitalisation for IV fluids and antibiotics - can kill
○ If neutropenia but well +/- prophylactic antibiotics (if < 0.7-1.0 x109 cells/L)
2) thrombocytopenia - usually not clinical significant
3) anaemia - common but rarely need intervention
In terms of alopecia and gastrointesinal effects of chemotherapy what occurs
ALOPECIA
- not significant problem, may coat change UNLESS Constantly growing hair coat = more significant alopecia - poodle
GASTROINTESTINAL
- Acute – vomiting, due to effects on CRTZ, vomiting centre.
- Delayed – vomiting, nausea, diarrhoea - most common
○ Usually approx. 3 days later (maybe same day)
GIVE - Anti-emetic and anti-diarrhoeal medications sent home +/- prophylactic use in some cases
Chemotherapy safety what possible effects and how to minimise direct vs indirect contact
- Increased risk of cancer ○ Damages DNA and predisposes for cancer - Effects on fertility and reproduction Direct - drug storage, PPE, spill kits, dont crush or compound pills Indirect ○ Gloves when cleaning urine/faeces ○ Wash hands after interacting with pet ○ Clean surfaces – dilute bleach - wash bedding separately
anaesthesia emergency risk factors and those specific to rabbits, cats and horses
Small Animal Risk factors - Referral centre vs primary care centre - Sickness (ASA Status) - Age (increasing) - Weight (under and over weight), Urgency - Type and length of procedure • Rabbits - Intubation and IV catheterisation are difficult - Prone to hypothermia • Cats - Difficult endotracheal intubation - Prone to hypothermia - Drug overdose Horses - type of surgery (GIT), duration, positioning, hypotension
What are the 3 main reasons for anaesthesia emergencies
1) human error
2) equipment failure
3) patient related factors
Human error in anaesthesia emergencies what occurs
- Inadequate patient examination and assessment
- Lack of familiarity with drugs and equipment
- Lack of attention
○ Failure in monitoring
○ Failure to recognize emergencies and respond - Incorrect drug administration
Equipment failure in anaesthesia emergencies what occurs
- Misassembled machine
- Oxygen -> Lack of oxygen OR Insufficient O2 flow
- Vaporiser - cannot store on the side
- CO2 absorber exhaustion - change soda lime -
Pop-off/APL valve - severe lung trauma ○ Left closed - Inappropriate fluid or drug rate administration
- Endotracheal tube complications - blocked, kinked, cuff infilation over (tracheal tear) or under (aspirate fluid)
Patient risk factors in anaesthesia emergencies
- Age
- Weight/BCS
- Systemic disease
○ Cardiac, respiratory, hepatic, renal, endocrine etc - Co-morbidities & concurrent conditions
○ Pregnancy, Trauma - ASA status
The ASA classification is an assessment of the patient’s pre-operative physical status
What are 6 complications surrounding induction period
1) drug reactions
2) drug over dosage
3) perivascular infection - thiopentone major irritant
4) apnoea
5) difficulty intubating
6) vomiting and regurgitation
List the 9 complications surrounding the maintenance period
1) Inadequate depth
2) Bradycardia
3) Hypotension
4) Tachycardia
5) Hypertension
6) hypoventilation
7) hypoxaemia
8) haemorrhage
9) cardiac arrest
What to do if you have inadequate depth of patient under anaesthesia
- Check the vaporiser
- Check the O2
- Check the ET tube
§ Oesophageal or endobronchial intubation
§ Cuff inflated? - Check ventilation - post-induction apnoea
- Check your catheter
- Do you need more background sedation?
Bradycardia what level in dog and cat, causes and treatment
HR < 50-70 bpm (dog and) <100 bpm (cat) Causes ○ CNS depression § Anaesthetic drugs, hypothermia, increased intracranial pressure ○ Cardiovascular failure § Hyperkalaemia, hypoxemia ○ Vagal reflex § Pressure on eye, viscera, stimulation of pharnyx/larynx Treatment ○ Determine cause and treat ○ Drugs - doesn't work if hypothermic Anticholinergic (glycopyrrolate or atropine)
Hypotension during monitoring of anaesthesia what levels causes and treatment
in horses more likely to die - Decreased arterial blood pressure ○ Systolic < 80mmHg ○ Mean < 60mmHg, < 70mmHg (in horses) Causes - Anaesthetic agents (isoflurane, acepromazine) ○ Hypovolaemia, haemorrhage ○ Myocardial damage ○ Peripheral vasodilation (Sepsis) Treatment aimed at the cause -> dopamine, fluid, vasopressors (noradrenalin)
Tachycardia and hypertension during monitoring anaesthesia how common and general cause
NOT COMMON
- Light depth of anaesthesia
○ Increase depth
FIX tachycardia like hypotension when hypertension not present
Hypercapnia during monitoring patient during anaesthesia what level leads to what, 3 causes and 3 treatment options
- Hypoventilation leading to hypercapnia (CO2 >60mmHg) ○ Low pH ○ Decreased oxygenation - Aponea if untreated will lead to hypoxia and cardiac arrest - 3 Main causes 1. Hypoventilation 2. rebreathing of CO2 3. increased production TREATMENT ○ Provide IPPV or mechanical ventilation ○ Reassess depth of anaesthesia ○ Try to correct the cause
Hypoxaemia during monitoring of anaesthetic what level, how assessed and treatment
• SPO2 <90% or PaO2 < 60mmHg - Assessed via pulse oximetry or arterial blood gas - Treatment based on cause ○ Low inspired O2 ○ Hypoventilation ○ Ventilation-perfusion mismatch ○ Shunt
Haemorrhage and cardiac arrest during monitoring of anaesthetic what bad and treatment
HAEMORRHAGE
- Acute haemorrhage => hypovolaemia => hypotension
- 10-20% reduction in blood volume = detectable
- 30-40% reduction in blood volume = life threatening
- Treatment
Initially crystalloid solution followed by blood transfusion (whole blood vs packed red cells)
CARDIAC ARREST
- recognition, recovery guidlines - basic life support, turn off anaesthetic agents, consider reversal medication
What are the 7 main complications surrounding the recovery period of anaesthetic
- Excitement/Dysphoria - further sedatives
- Pain
- Equine recovery
- Prolonged recovery
- Dyspnea
- Regurgitation and Vomiting
- Hypothermia
Pain during recovery of srugery what is important
- Appropriate analgesia should be part of a complete anaesthetic plan
- Difficult to decipher pain vs dysphoria in the immediate post-operative period
- Pain assessment
- Multi modal analgesia
○ Decreases recovery time
Prlonged recovery after surgery what causes and treatment
- Causes
○ Hypothermia, metabolic derangements (hypoglycaemia), altered mentation - Treatment
○ Provide supportive therapy (oxygen, ventilation, warming)
○ Drug reversal - Check blood glucose and electrolytes
Dyspnea in small animal and equine cause and treatment
Cats: Laryngospasm and oedema - Dog: Breed related and tracheal collapse - Treatment ○ Extend the neck > pull tongue ○ Provide O2 ○ Intubate ○ Tracheostomy Equine - development of nasal oedma - Prevention ○ Head elevated, Pre place nasal tube - Treatment ○ When safe re-anaethetise ○ Intubate
regurgitation and vomiting during recovery of anaesthetic what are the 3 main concerns and treatment options
Three concerns ○ Aspiration pneumonia ○ Ulcerative eophagitis and strictures ○ Nasal and pharyngeal irritation - Treatment in the anaethetised patient ○ Head positioning ○ Ensure cuff is well inflated ○ Suction Extubate when swallowing with cuff inflated
Hypothermia during recovery of anaesthetic what can lead to and treatment
- Severe hypothermia has negative consequences
- Peripheral vasoconstriction, reduced drug metabolism, decreased coagulation
- Treatment
○ Increasing room temp
○ Heating systems: warm air, warming blankets
○ Beware shock following too rapid rewarming
